Theoretical Research of Sof-dipole Resonances in Light Neutron-Rich Nuclei

轻富中子核中软偶极子共振的理论研究

基本信息

批准号：
12640246
负责人：
KATO Kiyoshi
金额：
$ 1.66万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

The purpose of this project is to obtain a theoretical conclusion about existence and observation of soft-dipole resonaces in ^6He and ^<11>Li whichare typical nuclei of light neutron rich nuclei. For this purpose, the following three problems were studied in these three years of 2000-2002 and desired results were successfully obtained :(1) Theoretical researches of soft-dipole resonances in three-body Coulomb breakup reactions. Using the complex scaling method, we developed a new theoretical framework to treat three-body breakup reactions. Applying this new method to ^6He and 11Li, we calculated the breakup cross sections where contributions from soft-dipole resonances are negligible.(2) Study of binding and excitation mechanisms by using an extended core+n+n model where internal degrees of freedom of the core cluster are taken into account. It was shown that the pairing correlations not only between valence neutrons but also between neutrons in the ^9Li core play an important role in the binding mechanism and a large amplitude of s-wave components.(3) Mechanism of appearance of s-wave anti-bound states. Analyses of s-wave anti-bound states in ^4He-n and ^9Li-n systems gave a clear relation between position of anti-bound poles and property of ^4He-n and ^9Li-npotentials.

本项目的目的是获得关于^6He和^<11>Li中软偶极子共振的存在和观测的理论结论，^6He和^11Li是典型的轻中子富核原子核。为此，2000-2002年三年间对以下三个问题进行了研究，并取得了预期成果：（1）三体库仑破裂反应中软偶极子共振的理论研究。使用复杂的标度方法，我们开发了一个新的理论框架来处理三体分解反应。将这种新方法应用于 ^6He 和 11Li，我们计算了软偶极子共振的贡献可以忽略不计的破碎截面。(2) 使用扩展的 core+n+n 模型研究结合和激发机制，其中内部自由度考虑到核心集群的数量。结果表明，^9Li核中不仅价中子之间的配对关系，而且中子之间的配对关系在结合机制和横波分量大幅度增加中发挥着重要作用。(3)横波反相的出现机制束缚态。对^4He-n和^9Li-n系统中横波反束缚态的分析给出了反束缚极位置与^4He-n和^9Li-n势的性质之间的清晰关系。